The invention is directed to a destructible container for a settable multi-component mass used for anchoring a fastening member in a borehole. The container is formed of an outer cartridge and an inner cartridge positioned within the outer cartridge with one of the cartridges filled with a resin component and filler materials of the mass and the other cartridge with a hardenable component and possibly with additional filler materials.
The chemical anchoring of fastening members using a settable mass or material has definite advantages as compared to a mechanical anchoring, such as where a dowel is secured by an expansion procedure in a receiving material. These advantages include the lack of an expansion pressrre developed in the receiving material and anchoring the fastening member where only minor edge distances in the receiving material are involved.
In previously known chemical anchoring procedures relatively highly viscous materials, such as a polyester resin, an epoxy resin or a polyurethane resin have been used as the settable material enclosed within a container. Where there has been insufficient cleaning of the borehole prior to the insertion of the settable material or where the receiving material is porous or has fine microfissures hardly discernable by the naked eye, the adhesion of such highly viscous resins with the receiving material is limited. Apart from the reduction in anchoring values, which can be determined immediately, unfavorable long time behavior can occur particularly where the fastening member undergoes alternating stresses. To overcome such disadvantages, the use of low viscosity, that is highly fluid resins, has been attempted, however, when used in boreholes directed vertically upwardly or horizontally, such material tends to leak or run out of the borehole prior to becoming set. To avoid the loss of the material it has been known to utilize a multichamber container and to fill it at the opening into the borehole with components of a particularly rapidly settable, foamable resin mixture. Such foamable masses, however, have a considerably lower strength so that it is necessary to use longer fastening members and the boreholes must be correspondingly deeper, which results in increased assembly time and material costs. Further, water is required for the foaming process and it is not always available in the different receiving materials in which the fastening member is to be secured.
Other options for sealing the opening to the borehole, such as plugs or the like, have proved to be unsuitable in actual practice, because they become damaged or destroyed when the fastening member is driven in which is usually effected by a rotational action.